00:01
So we want to know that the probability of a defective part is 1 out of 100 or 0 .01.
00:09
And we want to find an a, what's the probability that the first one, first defective, is the 10th one? well, what does that mean? that means that your first 9 you get, so defective is 1%, non -defective.
00:34
Defective is going to be .99.
00:37
So that means the first nine that you get are going to be non -defectives, and then the last one is going to be defective.
00:46
Now we can just type this in.
00:49
0 .99 to the 9th power, and then times .01.
00:55
We could also use some technology to do this as well, but we won't for this one.
01:00
I have one seven to five and i would think that that would be sufficient just to write that.
01:06
Now we want to find the probability that the first defective is either the first one you pick or the second or the third.
01:21
And so in that case, this again is geometric and we want to find the probability if it's the first one that's picked.
01:28
So that would be .01.
01:31
Or it could be the second one...